1. Field of the Invention
The present invention relates to vehicle access ramps and more particularly relates to ramps which are deployable from a position in which the ramp is stored below the vehicle floor to an extended, inclined position to assist disabled persons entering and exiting the vehicle.
There is a recognized need for access ramps or platforms which will assist persons, particularly disabled persons, in entering and exiting motor vehicles, either as a passenger or as a driver. The Americans With Disabilities Act has as a stated objective the removal of physical obstacles to those with handicaps or disabilities. Because of the stated objectives of this legislation and an increased public awareness and concern of the requirements of the disabled, there has been more emphasis in providing systems which assist a wheelchair occupant or other disabled person a convenient and safe way of entering or leaving a motor vehicle. In many cases, once access to the vehicle is obtained, the person can operate the vehicle which may be provided with special operator controls.
2. Description of Related Art
Some of the earlier design efforts in this area include power-operated ramps to facilitate wheelchair passengers in entering and leaving public vehicles such as buses. U.S. Pat. No. 4,131,209 discloses a ramp for a motor bus which, when the door is opened, accommodates lateral outward extension of a ramp from a normally stowed position below the floor of the bus. A portion of the ramp adjacent its outer end serves as a step for entering the bus when the ramp is in the stowed position. The device is powered by a motorized lead screw. When extended, the ramp moves outwardly through the entranceway and automatically tilts upwardly towards its inner end to provide an inclined platform from the sidewalk or roadway to the vehicle. A further improvement to this ramp is shown in U.S. Pat. No. 4,685,858.
U. S. Pat. No. 4,479,753 discloses another approach to the problem of providing accessibility to vehicles. A lift is shown which may be retrofit to a van which lift is hinged on a vertical axis to a door post adjacent the door hinge. A horizontal carrier allows the unit to slide to clear the vehicle structure and then a vertical carrier descends from the horizontal carrier powered by a hydraulic actuator. A folding platform then swings down on its horizontal hinge along the lower edge of the vertical carrier. In the deployed position, the platform is vertically moved on the vertical carrier and is subsequently stowed by swinging the platform vertically against the horizontal and vertical carriers so that the entire lift package when not deployed is conveniently stowable.
Another type of vehicle-mounted access ramp for a wheelchair user is shown in U.S. Pat. No. 3,874,527. In this patent, the vehicle door is modified to hinge about a horizontal axis along or below the lower edge of the door. The inner surface of the door is modified to provide a ramp surface. The door is raised and lowered by a power assembly. Approach ramp pivots along the normal upper door edge provides a smooth ramp surface from the ground to the inner door surface when the door is lowered.
U.S. Pat. No. 4,827,548 discloses an extendable and retractable ramp assembly for facilitating wheelchair passengers to and from a bus or van. The invention has an extendable and retractable ramp which includes a power actuating mechanism disposed in the vehicle which includes a track mechanism and roller elements mounted on the ramp which elevate the inner end of the ramp to the approximate level of the floor of the bus or van.
Further improvements in ramps of this type are found in U.S. Pat. No. 5,160,236 which ramp has been commercialized by the assignee of this application, Care Concepts, Inc., of Phoenix, Ariz. This patent shows a retractable van side door ramp which has a short base end section and a longer outer end section which are pivotally connected. The ramp assembly is mounted from the floor structure of the van and is extendable and retractable at the side of the van below the door opening. The ramp assembly is supported during a portion of the extension and the retraction and as the ramp approaches the fully extended position, the outer ramp platform pivots to a position on the ground or curb so as to not shovel. The reverse operation takes place during retraction. The ramp may be powered by various manual or mechanical drive arrangements including electric motors or cable and gear systems.
While the above patents as well as various patents disclosed therein disclose various systems for assisting disabled persons and persons confined to a wheelchair in entering and exiting a motor vehicle, there nevertheless exists a need for a simplified and efficient ramp which provides vehicle accessibility and which ramp complies with the requirements and spirit of the Americans With Disabilities Act.